Technological advancements such as the Internet, video on demand, high-definition television (HDTV), video conferencing, multiple telephone lines, etc. and the need or desire for better quality video and audio have created the demand for more and more bandwidth at businesses and homes. In response to this demand, telecommunications providers and others began installing fiber optic telecommunications cables with extremely large bandwidths to replace or supplement traditional copper and coaxial systems. Fiber-optic cable is known in the art to one of ordinary skill and is generally comprised of a plurality of fiber-optic strands and buffering material encased in one or more layers of shielding material. Initially, because of the cost of fiber optic cable, head-end equipment and terminating equipment, the fiber optic cable was extended only to large businesses and local exchange panels where service to small business, homes and other residential dwellings was still occurring through copper wires. However, bandwidth demand has continued to grow and costs of fiber-optic cable and equipments has decreased and consequentially, telecommunications providers and others have begun to install fiber optic cable all the way to small businesses, homes and other residential dwellings. This is generally referred to as fiber to the premises (FTTP).
In many instances, passive optical networks (PONs) are used to provide FTTP as well as fiber to the curb (FTTC) and fiber to the neighborhood (FTTN). PON is a fiber to the premises configuration in which unpowered optical splitters are used to enable a single optical fiber to serve multiple premises. The advantages to PON include that it is a fiber-based transmission network that contains no active electronics and that a single fiber may provide service to multiple premises. It is a point-to-multipoint configuration, which reduces the amount of fiber required compared with point-to-point configurations. However, the very design that makes PONs attractive from a design and cost standpoint creates challenges when testing a PON, especially when the PON is on-line or active. Prior technologies have used a moveable mirror to selectively reflect light back into a fiber for test purposes. However, these devices reflect the light at all wavelengths back onto the fiber. This allows the fiber to be tested by an instrument at the other end of the fiber, but this test cannot be made without disrupting traffic on the fiber. Also, these devices have not been designed to work in PONs. Instead they have been used in point-to-point fiber networks or Fiber Distributed Data Interface (FDDI) networks (e.g., token ring).